The Role of Gases in Groundwater Contamination and Remediation

点击翻译按钮获取中文摘要

Groundwater is a vital natural resource. Approximately 10 million Canadians rely on groundwater as a source of drinking water. It is also an important link between surface water and deeper regional systems, and is a source of water for Canadian industries, including agriculture and oil and gas. The quality of our groundwater is threatened by contamination. There are tens of thousands of contaminated sites in Canada, many of which are brownfield properties located in urban centres and along waterfronts. The cost to clean up these sites is substantial, and likely totals tens of billions of dollars. Gases in the subsurface play an important, but often underappreciated, role in groundwater contamination. For example, gases can be created naturally or by remediation technologies, and they affect the flow of groundwater (by reducing permeability) as well as the transport and reaction of contaminants (by mass transfer between the gas and groundwater). Gases can also be contaminants themselves. For example, the rapid increase in shale gas extraction has led to increased concern over environmental impacts, including the contamination of drinking water aquifers by methane gas.